This invention relates generally to fluid driven turbines, and more particularly to what are described herein as variable phase fluid driven turbines.
Turbines are widely used in industry to convert the energy in liquid streams or gas streams to shaft power. Less common, but also used are turbines to convert the energy in two-phase (gas and liquid) streams to shaft power. The turbines for each type of stream are unique to that stream. That is, a turbine designed to be gas driven is not readily usable for liquid or two-phase flow. For example attempts to use radial inflow gas turbines for two-phase flow have resulted in poor performance and damage because the direction of centrifugal body forces is such as to throw liquid backwards into the nozzle blades.
Certain application for turbines require the use of different types of fluid streams for differing conditions. For example, a low temperature geothermal power system may require use of a gas stream or a two-phase flow stream, depending upon the temperature and working fluid used in the power producing cycle. To provide an efficient power conversion system, a new or specialized turbine must be designed, manufactured and qualified for each application. This is costly and time consuming and reduces flexibility, if the thermal characteristics of a given application change with time. There is need for an efficient turbine that can be driven by gas, or liquid or two-phase fluid flow.